Intangible assets as of December 31, 2024, consist of the following (in millions):


	Cost		Accumulated Amortization		Net
Customer relationships	$	6,296	$	(5,056)	$	1,240
Trademarks and other	148		(70)		78
Total Intangible assets, net	$	6,444	$	(5,126)	$	1,318

Intangible assets as of December 31, 2023, consist of the following (in millions):


	Cost		Accumulated Amortization		Net
Customer relationships	$	6,326	$	(4,583)	$	1,743
Trademarks and other	142		(62)		80
Total Intangible assets, net	$	6,468	$	(4,645)	$	1,823

Amortization expense for intangible assets with finite lives was $641 million, $467 million and $486 million for the years ended December 31, 2024, 2023 and 2022, respectively.

Estimated amortization of intangible assets for the next five years is as follows (in millions):


2025	$	582
2026	214
2027	182
2028	161
2029	95